The present invention concerns a novel method and device for retrieving embolic coils used for treating an aneurysm of a patient.
A well known method of treating an aneurysm of a vessel wall includes the placement of a number of detachable embolic coils within the aneurysm. Multiple coils are employed during the procedure in an effort to completely embolize the vessel defect. Typically, a deployment device is used to introduce the coils, one by one, via a microcatheter, into the aneurysm. Occasionally during a procedure, an earlier introduced coil may become displaced from the aneurysm and protrude into the parent vessel. This coil protrusion can have a disastrous effect on the patient. Because the embolic coil is in the blood flow, thrombus begins to form around the coil which can potentially occlude the vessel initiating an ischemic attack or the clot may break off, flow distal and occlude other vessels leading to ischemia in another part of the brain. Therefore it is imperative that the misplaced coil be removed.
Certain prior art coil retrieval devices use a loop or snare configuration to try to lasso the misplaced coil. Since the misplaced coil is sometimes a loop, the physician often has difficulty trying to lasso these coils which may add to the procedure time and cause potential complications.
It is, therefore, an object of the invention to provide a novel method for retrieving embolic coils.
It is a further object of the invention to provide a method and device for retrieving embolic coils in which the embolic coils are secured in a retrieval device and prevented from becoming dislodged.
Another object of the present invention is to provide a tool for the physician to enable the physician to rapidly retrieve a misplaced embolic coil.
A further object of the present invention is to provide a pushable wire device for retrieving embolic coils that is simple in operation and relatively easy to manufacture.
Other objects and advantages of the present invention will become apparent as the description proceeds.
In accordance with the present invention, a method is disclosed for retrieving embolic coils used for treating an aneurysm. The method comprises the steps of providing a wire device that is pushable through a microcatheter and has a flexible distal portion comprising a distal collapsible arm with a latch member carried by the arm. A microcatheter is introduced into a patient""s vessel leading to the aneurysm. The wire device is introduced into the microcatheter whereby the arm collapses while it is within the microcatheter. The distal end of the wire device is pushed through the microcatheter whereby the arm opens when it extends out of the distal end of the microcatheter. The latch member is manipulated so that it engages an embolic coil to be retrieved. The latch-engaged embolic coil and the wire device are withdrawn through the catheter whereby the arm becomes collapsed as the arm is withdrawn through the catheter.
In the illustrative embodiment, the flexible distal portion comprises a pair of distal collapsible arms with a latch member carried by at least one of the arms.
In the illustrative embodiment, the wire device has a stiffer proximal portion than the distal portion. A portion of the collapsible arm is radiopaque and the arm and latch are formed from a composition comprising nitinol.
In accordance with the illustrative embodiment, a medical device is provided for retrieving embolic coils implanted in a patient. The medical device of the illustrative embodiment comprises a wire device that is pushable through a microcatheter and has a flexible distal portion comprising a pair of distal collapsible arms with an angled latch member carried by one of the arms.
A more detailed explanation of the invention is provided in the following description and claims, and is illustrated in the accompanying drawings.